Genève resident Daniel Hauser was the Swiss Romande (Romandy) champion in welterweight freestyle wrestling in 1951, and the runner-up in the same weight class at the 1950 national championships. Selected to the Swiss Olympic wrestling team to compete in Helsinki 1952, Hauser lost his only match by unanimous decision to Anton Mackowiak of Germany. Hauser continued to be active throughout the decade, winning the national freestyle welterweight title in 1955 and 1957. In 1959, he was selected as one of the Swiss representatives to compete at the 1959 World Championships held in Tehran, where he was defeated by İsmail Ogan for the bronze medal in the welterweight freestyle competition. Hauser continued to compete into the 1960s.